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virtio_blk.c
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// SPDX-License-Identifier: GPL-2.0-only
//#define DEBUG
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/hdreg.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
#include <linux/virtio.h>
#include <linux/virtio_blk.h>
#include <linux/scatterlist.h>
#include <linux/string_helpers.h>
#include <linux/idr.h>
#include <linux/blk-mq.h>
#include <linux/blk-mq-virtio.h>
#include <linux/numa.h>
#include <linux/vmalloc.h>
#include <uapi/linux/virtio_ring.h>
#define PART_BITS 4
#define VQ_NAME_LEN 16
#define MAX_DISCARD_SEGMENTS 256u
/* The maximum number of sg elements that fit into a virtqueue */
#define VIRTIO_BLK_MAX_SG_ELEMS 32768
#ifdef CONFIG_ARCH_NO_SG_CHAIN
#define VIRTIO_BLK_INLINE_SG_CNT 0
#else
#define VIRTIO_BLK_INLINE_SG_CNT 2
#endif
static unsigned int num_request_queues;
module_param(num_request_queues, uint, 0644);
MODULE_PARM_DESC(num_request_queues,
"Limit the number of request queues to use for blk device. "
"0 for no limit. "
"Values > nr_cpu_ids truncated to nr_cpu_ids.");
static unsigned int poll_queues;
module_param(poll_queues, uint, 0644);
MODULE_PARM_DESC(poll_queues, "The number of dedicated virtqueues for polling I/O");
static int major;
static DEFINE_IDA(vd_index_ida);
static struct workqueue_struct *virtblk_wq;
struct virtio_blk_vq {
struct virtqueue *vq;
spinlock_t lock;
char name[VQ_NAME_LEN];
} ____cacheline_aligned_in_smp;
struct virtio_blk {
/*
* This mutex must be held by anything that may run after
* virtblk_remove() sets vblk->vdev to NULL.
*
* blk-mq, virtqueue processing, and sysfs attribute code paths are
* shut down before vblk->vdev is set to NULL and therefore do not need
* to hold this mutex.
*/
struct mutex vdev_mutex;
struct virtio_device *vdev;
/* The disk structure for the kernel. */
struct gendisk *disk;
/* Block layer tags. */
struct blk_mq_tag_set tag_set;
/* Process context for config space updates */
struct work_struct config_work;
/* Ida index - used to track minor number allocations. */
int index;
/* num of vqs */
int num_vqs;
int io_queues[HCTX_MAX_TYPES];
struct virtio_blk_vq *vqs;
/* For zoned device */
unsigned int zone_sectors;
};
struct virtblk_req {
/* Out header */
struct virtio_blk_outhdr out_hdr;
/* In header */
union {
u8 status;
/*
* The zone append command has an extended in header.
* The status field in zone_append_in_hdr must always
* be the last byte.
*/
struct {
__virtio64 sector;
u8 status;
} zone_append;
} in_hdr;
size_t in_hdr_len;
struct sg_table sg_table;
struct scatterlist sg[];
};
static inline blk_status_t virtblk_result(u8 status)
{
switch (status) {
case VIRTIO_BLK_S_OK:
return BLK_STS_OK;
case VIRTIO_BLK_S_UNSUPP:
return BLK_STS_NOTSUPP;
case VIRTIO_BLK_S_ZONE_OPEN_RESOURCE:
return BLK_STS_ZONE_OPEN_RESOURCE;
case VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE:
return BLK_STS_ZONE_ACTIVE_RESOURCE;
case VIRTIO_BLK_S_IOERR:
case VIRTIO_BLK_S_ZONE_UNALIGNED_WP:
default:
return BLK_STS_IOERR;
}
}
static inline struct virtio_blk_vq *get_virtio_blk_vq(struct blk_mq_hw_ctx *hctx)
{
struct virtio_blk *vblk = hctx->queue->queuedata;
struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
return vq;
}
static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr)
{
struct scatterlist out_hdr, in_hdr, *sgs[3];
unsigned int num_out = 0, num_in = 0;
sg_init_one(&out_hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
sgs[num_out++] = &out_hdr;
if (vbr->sg_table.nents) {
if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
sgs[num_out++] = vbr->sg_table.sgl;
else
sgs[num_out + num_in++] = vbr->sg_table.sgl;
}
sg_init_one(&in_hdr, &vbr->in_hdr.status, vbr->in_hdr_len);
sgs[num_out + num_in++] = &in_hdr;
return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
}
static int virtblk_setup_discard_write_zeroes_erase(struct request *req, bool unmap)
{
unsigned short segments = blk_rq_nr_discard_segments(req);
unsigned short n = 0;
struct virtio_blk_discard_write_zeroes *range;
struct bio *bio;
u32 flags = 0;
if (unmap)
flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP;
range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC);
if (!range)
return -ENOMEM;
/*
* Single max discard segment means multi-range discard isn't
* supported, and block layer only runs contiguity merge like
* normal RW request. So we can't reply on bio for retrieving
* each range info.
*/
if (queue_max_discard_segments(req->q) == 1) {
range[0].flags = cpu_to_le32(flags);
range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req));
range[0].sector = cpu_to_le64(blk_rq_pos(req));
n = 1;
} else {
__rq_for_each_bio(bio, req) {
u64 sector = bio->bi_iter.bi_sector;
u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT;
range[n].flags = cpu_to_le32(flags);
range[n].num_sectors = cpu_to_le32(num_sectors);
range[n].sector = cpu_to_le64(sector);
n++;
}
}
WARN_ON_ONCE(n != segments);
bvec_set_virt(&req->special_vec, range, sizeof(*range) * segments);
req->rq_flags |= RQF_SPECIAL_PAYLOAD;
return 0;
}
static void virtblk_unmap_data(struct request *req, struct virtblk_req *vbr)
{
if (blk_rq_nr_phys_segments(req))
sg_free_table_chained(&vbr->sg_table,
VIRTIO_BLK_INLINE_SG_CNT);
}
static int virtblk_map_data(struct blk_mq_hw_ctx *hctx, struct request *req,
struct virtblk_req *vbr)
{
int err;
if (!blk_rq_nr_phys_segments(req))
return 0;
vbr->sg_table.sgl = vbr->sg;
err = sg_alloc_table_chained(&vbr->sg_table,
blk_rq_nr_phys_segments(req),
vbr->sg_table.sgl,
VIRTIO_BLK_INLINE_SG_CNT);
if (unlikely(err))
return -ENOMEM;
return blk_rq_map_sg(hctx->queue, req, vbr->sg_table.sgl);
}
static void virtblk_cleanup_cmd(struct request *req)
{
if (req->rq_flags & RQF_SPECIAL_PAYLOAD)
kfree(bvec_virt(&req->special_vec));
}
static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
struct request *req,
struct virtblk_req *vbr)
{
size_t in_hdr_len = sizeof(vbr->in_hdr.status);
bool unmap = false;
u32 type;
u64 sector = 0;
if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) && op_is_zone_mgmt(req_op(req)))
return BLK_STS_NOTSUPP;
/* Set fields for all request types */
vbr->out_hdr.ioprio = cpu_to_virtio32(vdev, req_get_ioprio(req));
switch (req_op(req)) {
case REQ_OP_READ:
type = VIRTIO_BLK_T_IN;
sector = blk_rq_pos(req);
break;
case REQ_OP_WRITE:
type = VIRTIO_BLK_T_OUT;
sector = blk_rq_pos(req);
break;
case REQ_OP_FLUSH:
type = VIRTIO_BLK_T_FLUSH;
break;
case REQ_OP_DISCARD:
type = VIRTIO_BLK_T_DISCARD;
break;
case REQ_OP_WRITE_ZEROES:
type = VIRTIO_BLK_T_WRITE_ZEROES;
unmap = !(req->cmd_flags & REQ_NOUNMAP);
break;
case REQ_OP_SECURE_ERASE:
type = VIRTIO_BLK_T_SECURE_ERASE;
break;
case REQ_OP_ZONE_OPEN:
type = VIRTIO_BLK_T_ZONE_OPEN;
sector = blk_rq_pos(req);
break;
case REQ_OP_ZONE_CLOSE:
type = VIRTIO_BLK_T_ZONE_CLOSE;
sector = blk_rq_pos(req);
break;
case REQ_OP_ZONE_FINISH:
type = VIRTIO_BLK_T_ZONE_FINISH;
sector = blk_rq_pos(req);
break;
case REQ_OP_ZONE_APPEND:
type = VIRTIO_BLK_T_ZONE_APPEND;
sector = blk_rq_pos(req);
in_hdr_len = sizeof(vbr->in_hdr.zone_append);
break;
case REQ_OP_ZONE_RESET:
type = VIRTIO_BLK_T_ZONE_RESET;
sector = blk_rq_pos(req);
break;
case REQ_OP_ZONE_RESET_ALL:
type = VIRTIO_BLK_T_ZONE_RESET_ALL;
break;
case REQ_OP_DRV_IN:
/*
* Out header has already been prepared by the caller (virtblk_get_id()
* or virtblk_submit_zone_report()), nothing to do here.
*/
return 0;
default:
WARN_ON_ONCE(1);
return BLK_STS_IOERR;
}
/* Set fields for non-REQ_OP_DRV_IN request types */
vbr->in_hdr_len = in_hdr_len;
vbr->out_hdr.type = cpu_to_virtio32(vdev, type);
vbr->out_hdr.sector = cpu_to_virtio64(vdev, sector);
if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES ||
type == VIRTIO_BLK_T_SECURE_ERASE) {
if (virtblk_setup_discard_write_zeroes_erase(req, unmap))
return BLK_STS_RESOURCE;
}
return 0;
}
/*
* The status byte is always the last byte of the virtblk request
* in-header. This helper fetches its value for all in-header formats
* that are currently defined.
*/
static inline u8 virtblk_vbr_status(struct virtblk_req *vbr)
{
return *((u8 *)&vbr->in_hdr + vbr->in_hdr_len - 1);
}
static inline void virtblk_request_done(struct request *req)
{
struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
blk_status_t status = virtblk_result(virtblk_vbr_status(vbr));
struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
virtblk_unmap_data(req, vbr);
virtblk_cleanup_cmd(req);
if (req_op(req) == REQ_OP_ZONE_APPEND)
req->__sector = virtio64_to_cpu(vblk->vdev,
vbr->in_hdr.zone_append.sector);
blk_mq_end_request(req, status);
}
static void virtblk_done(struct virtqueue *vq)
{
struct virtio_blk *vblk = vq->vdev->priv;
bool req_done = false;
int qid = vq->index;
struct virtblk_req *vbr;
unsigned long flags;
unsigned int len;
spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
do {
virtqueue_disable_cb(vq);
while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
struct request *req = blk_mq_rq_from_pdu(vbr);
if (likely(!blk_should_fake_timeout(req->q)))
blk_mq_complete_request(req);
req_done = true;
}
} while (!virtqueue_enable_cb(vq));
/* In case queue is stopped waiting for more buffers. */
if (req_done)
blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
}
static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx)
{
struct virtio_blk *vblk = hctx->queue->queuedata;
struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num];
bool kick;
spin_lock_irq(&vq->lock);
kick = virtqueue_kick_prepare(vq->vq);
spin_unlock_irq(&vq->lock);
if (kick)
virtqueue_notify(vq->vq);
}
static blk_status_t virtblk_fail_to_queue(struct request *req, int rc)
{
virtblk_cleanup_cmd(req);
switch (rc) {
case -ENOSPC:
return BLK_STS_DEV_RESOURCE;
case -ENOMEM:
return BLK_STS_RESOURCE;
default:
return BLK_STS_IOERR;
}
}
static blk_status_t virtblk_prep_rq(struct blk_mq_hw_ctx *hctx,
struct virtio_blk *vblk,
struct request *req,
struct virtblk_req *vbr)
{
blk_status_t status;
int num;
status = virtblk_setup_cmd(vblk->vdev, req, vbr);
if (unlikely(status))
return status;
num = virtblk_map_data(hctx, req, vbr);
if (unlikely(num < 0))
return virtblk_fail_to_queue(req, -ENOMEM);
vbr->sg_table.nents = num;
blk_mq_start_request(req);
return BLK_STS_OK;
}
static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
const struct blk_mq_queue_data *bd)
{
struct virtio_blk *vblk = hctx->queue->queuedata;
struct request *req = bd->rq;
struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
unsigned long flags;
int qid = hctx->queue_num;
bool notify = false;
blk_status_t status;
int err;
status = virtblk_prep_rq(hctx, vblk, req, vbr);
if (unlikely(status))
return status;
spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
err = virtblk_add_req(vblk->vqs[qid].vq, vbr);
if (err) {
virtqueue_kick(vblk->vqs[qid].vq);
/* Don't stop the queue if -ENOMEM: we may have failed to
* bounce the buffer due to global resource outage.
*/
if (err == -ENOSPC)
blk_mq_stop_hw_queue(hctx);
spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
virtblk_unmap_data(req, vbr);
return virtblk_fail_to_queue(req, err);
}
if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
notify = true;
spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
if (notify)
virtqueue_notify(vblk->vqs[qid].vq);
return BLK_STS_OK;
}
static bool virtblk_prep_rq_batch(struct request *req)
{
struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
return virtblk_prep_rq(req->mq_hctx, vblk, req, vbr) == BLK_STS_OK;
}
static bool virtblk_add_req_batch(struct virtio_blk_vq *vq,
struct request **rqlist)
{
unsigned long flags;
int err;
bool kick;
spin_lock_irqsave(&vq->lock, flags);
while (!rq_list_empty(*rqlist)) {
struct request *req = rq_list_pop(rqlist);
struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
err = virtblk_add_req(vq->vq, vbr);
if (err) {
virtblk_unmap_data(req, vbr);
virtblk_cleanup_cmd(req);
blk_mq_requeue_request(req, true);
}
}
kick = virtqueue_kick_prepare(vq->vq);
spin_unlock_irqrestore(&vq->lock, flags);
return kick;
}
static void virtio_queue_rqs(struct request **rqlist)
{
struct request *req, *next, *prev = NULL;
struct request *requeue_list = NULL;
rq_list_for_each_safe(rqlist, req, next) {
struct virtio_blk_vq *vq = get_virtio_blk_vq(req->mq_hctx);
bool kick;
if (!virtblk_prep_rq_batch(req)) {
rq_list_move(rqlist, &requeue_list, req, prev);
req = prev;
if (!req)
continue;
}
if (!next || req->mq_hctx != next->mq_hctx) {
req->rq_next = NULL;
kick = virtblk_add_req_batch(vq, rqlist);
if (kick)
virtqueue_notify(vq->vq);
*rqlist = next;
prev = NULL;
} else
prev = req;
}
*rqlist = requeue_list;
}
#ifdef CONFIG_BLK_DEV_ZONED
static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk,
unsigned int nr_zones,
size_t *buflen)
{
struct request_queue *q = vblk->disk->queue;
size_t bufsize;
void *buf;
nr_zones = min_t(unsigned int, nr_zones,
get_capacity(vblk->disk) >> ilog2(vblk->zone_sectors));
bufsize = sizeof(struct virtio_blk_zone_report) +
nr_zones * sizeof(struct virtio_blk_zone_descriptor);
bufsize = min_t(size_t, bufsize,
queue_max_hw_sectors(q) << SECTOR_SHIFT);
bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
while (bufsize >= sizeof(struct virtio_blk_zone_report)) {
buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY);
if (buf) {
*buflen = bufsize;
return buf;
}
bufsize >>= 1;
}
return NULL;
}
static int virtblk_submit_zone_report(struct virtio_blk *vblk,
char *report_buf, size_t report_len,
sector_t sector)
{
struct request_queue *q = vblk->disk->queue;
struct request *req;
struct virtblk_req *vbr;
int err;
req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0);
if (IS_ERR(req))
return PTR_ERR(req);
vbr = blk_mq_rq_to_pdu(req);
vbr->in_hdr_len = sizeof(vbr->in_hdr.status);
vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT);
vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector);
err = blk_rq_map_kern(q, req, report_buf, report_len, GFP_KERNEL);
if (err)
goto out;
blk_execute_rq(req, false);
err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status));
out:
blk_mq_free_request(req);
return err;
}
static int virtblk_parse_zone(struct virtio_blk *vblk,
struct virtio_blk_zone_descriptor *entry,
unsigned int idx, report_zones_cb cb, void *data)
{
struct blk_zone zone = { };
zone.start = virtio64_to_cpu(vblk->vdev, entry->z_start);
if (zone.start + vblk->zone_sectors <= get_capacity(vblk->disk))
zone.len = vblk->zone_sectors;
else
zone.len = get_capacity(vblk->disk) - zone.start;
zone.capacity = virtio64_to_cpu(vblk->vdev, entry->z_cap);
zone.wp = virtio64_to_cpu(vblk->vdev, entry->z_wp);
switch (entry->z_type) {
case VIRTIO_BLK_ZT_SWR:
zone.type = BLK_ZONE_TYPE_SEQWRITE_REQ;
break;
case VIRTIO_BLK_ZT_SWP:
zone.type = BLK_ZONE_TYPE_SEQWRITE_PREF;
break;
case VIRTIO_BLK_ZT_CONV:
zone.type = BLK_ZONE_TYPE_CONVENTIONAL;
break;
default:
dev_err(&vblk->vdev->dev, "zone %llu: invalid type %#x\n",
zone.start, entry->z_type);
return -EIO;
}
switch (entry->z_state) {
case VIRTIO_BLK_ZS_EMPTY:
zone.cond = BLK_ZONE_COND_EMPTY;
break;
case VIRTIO_BLK_ZS_CLOSED:
zone.cond = BLK_ZONE_COND_CLOSED;
break;
case VIRTIO_BLK_ZS_FULL:
zone.cond = BLK_ZONE_COND_FULL;
zone.wp = zone.start + zone.len;
break;
case VIRTIO_BLK_ZS_EOPEN:
zone.cond = BLK_ZONE_COND_EXP_OPEN;
break;
case VIRTIO_BLK_ZS_IOPEN:
zone.cond = BLK_ZONE_COND_IMP_OPEN;
break;
case VIRTIO_BLK_ZS_NOT_WP:
zone.cond = BLK_ZONE_COND_NOT_WP;
break;
case VIRTIO_BLK_ZS_RDONLY:
zone.cond = BLK_ZONE_COND_READONLY;
zone.wp = ULONG_MAX;
break;
case VIRTIO_BLK_ZS_OFFLINE:
zone.cond = BLK_ZONE_COND_OFFLINE;
zone.wp = ULONG_MAX;
break;
default:
dev_err(&vblk->vdev->dev, "zone %llu: invalid condition %#x\n",
zone.start, entry->z_state);
return -EIO;
}
/*
* The callback below checks the validity of the reported
* entry data, no need to further validate it here.
*/
return cb(&zone, idx, data);
}
static int virtblk_report_zones(struct gendisk *disk, sector_t sector,
unsigned int nr_zones, report_zones_cb cb,
void *data)
{
struct virtio_blk *vblk = disk->private_data;
struct virtio_blk_zone_report *report;
unsigned long long nz, i;
size_t buflen;
unsigned int zone_idx = 0;
int ret;
if (WARN_ON_ONCE(!vblk->zone_sectors))
return -EOPNOTSUPP;
report = virtblk_alloc_report_buffer(vblk, nr_zones, &buflen);
if (!report)
return -ENOMEM;
mutex_lock(&vblk->vdev_mutex);
if (!vblk->vdev) {
ret = -ENXIO;
goto fail_report;
}
while (zone_idx < nr_zones && sector < get_capacity(vblk->disk)) {
memset(report, 0, buflen);
ret = virtblk_submit_zone_report(vblk, (char *)report,
buflen, sector);
if (ret)
goto fail_report;
nz = min_t(u64, virtio64_to_cpu(vblk->vdev, report->nr_zones),
nr_zones);
if (!nz)
break;
for (i = 0; i < nz && zone_idx < nr_zones; i++) {
ret = virtblk_parse_zone(vblk, &report->zones[i],
zone_idx, cb, data);
if (ret)
goto fail_report;
sector = virtio64_to_cpu(vblk->vdev,
report->zones[i].z_start) +
vblk->zone_sectors;
zone_idx++;
}
}
if (zone_idx > 0)
ret = zone_idx;
else
ret = -EINVAL;
fail_report:
mutex_unlock(&vblk->vdev_mutex);
kvfree(report);
return ret;
}
static int virtblk_read_zoned_limits(struct virtio_blk *vblk,
struct queue_limits *lim)
{
struct virtio_device *vdev = vblk->vdev;
u32 v, wg;
dev_dbg(&vdev->dev, "probing host-managed zoned device\n");
lim->zoned = true;
virtio_cread(vdev, struct virtio_blk_config,
zoned.max_open_zones, &v);
lim->max_open_zones = v;
dev_dbg(&vdev->dev, "max open zones = %u\n", v);
virtio_cread(vdev, struct virtio_blk_config,
zoned.max_active_zones, &v);
lim->max_active_zones = v;
dev_dbg(&vdev->dev, "max active zones = %u\n", v);
virtio_cread(vdev, struct virtio_blk_config,
zoned.write_granularity, &wg);
if (!wg) {
dev_warn(&vdev->dev, "zero write granularity reported\n");
return -ENODEV;
}
lim->physical_block_size = wg;
lim->io_min = wg;
dev_dbg(&vdev->dev, "write granularity = %u\n", wg);
/*
* virtio ZBD specification doesn't require zones to be a power of
* two sectors in size, but the code in this driver expects that.
*/
virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors,
&vblk->zone_sectors);
if (vblk->zone_sectors == 0 || !is_power_of_2(vblk->zone_sectors)) {
dev_err(&vdev->dev,
"zoned device with non power of two zone size %u\n",
vblk->zone_sectors);
return -ENODEV;
}
lim->chunk_sectors = vblk->zone_sectors;
dev_dbg(&vdev->dev, "zone sectors = %u\n", vblk->zone_sectors);
if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) {
dev_warn(&vblk->vdev->dev,
"ignoring negotiated F_DISCARD for zoned device\n");
lim->max_hw_discard_sectors = 0;
}
virtio_cread(vdev, struct virtio_blk_config,
zoned.max_append_sectors, &v);
if (!v) {
dev_warn(&vdev->dev, "zero max_append_sectors reported\n");
return -ENODEV;
}
if ((v << SECTOR_SHIFT) < wg) {
dev_err(&vdev->dev,
"write granularity %u exceeds max_append_sectors %u limit\n",
wg, v);
return -ENODEV;
}
lim->max_zone_append_sectors = v;
dev_dbg(&vdev->dev, "max append sectors = %u\n", v);
return 0;
}
#else
/*
* Zoned block device support is not configured in this kernel, host-managed
* zoned devices can't be supported.
*/
#define virtblk_report_zones NULL
static inline int virtblk_read_zoned_limits(struct virtio_blk *vblk,
struct queue_limits *lim)
{
dev_err(&vblk->vdev->dev,
"virtio_blk: zoned devices are not supported");
return -EOPNOTSUPP;
}
#endif /* CONFIG_BLK_DEV_ZONED */
/* return id (s/n) string for *disk to *id_str
*/
static int virtblk_get_id(struct gendisk *disk, char *id_str)
{
struct virtio_blk *vblk = disk->private_data;
struct request_queue *q = vblk->disk->queue;
struct request *req;
struct virtblk_req *vbr;
int err;
req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0);
if (IS_ERR(req))
return PTR_ERR(req);
vbr = blk_mq_rq_to_pdu(req);
vbr->in_hdr_len = sizeof(vbr->in_hdr.status);
vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID);
vbr->out_hdr.sector = 0;
err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL);
if (err)
goto out;
blk_execute_rq(req, false);
err = blk_status_to_errno(virtblk_result(vbr->in_hdr.status));
out:
blk_mq_free_request(req);
return err;
}
/* We provide getgeo only to please some old bootloader/partitioning tools */
static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
{
struct virtio_blk *vblk = bd->bd_disk->private_data;
int ret = 0;
mutex_lock(&vblk->vdev_mutex);
if (!vblk->vdev) {
ret = -ENXIO;
goto out;
}
/* see if the host passed in geometry config */
if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
virtio_cread(vblk->vdev, struct virtio_blk_config,
geometry.cylinders, &geo->cylinders);
virtio_cread(vblk->vdev, struct virtio_blk_config,
geometry.heads, &geo->heads);
virtio_cread(vblk->vdev, struct virtio_blk_config,
geometry.sectors, &geo->sectors);
} else {
/* some standard values, similar to sd */
geo->heads = 1 << 6;
geo->sectors = 1 << 5;
geo->cylinders = get_capacity(bd->bd_disk) >> 11;
}
out:
mutex_unlock(&vblk->vdev_mutex);
return ret;
}
static void virtblk_free_disk(struct gendisk *disk)
{
struct virtio_blk *vblk = disk->private_data;
ida_free(&vd_index_ida, vblk->index);
mutex_destroy(&vblk->vdev_mutex);
kfree(vblk);
}
static const struct block_device_operations virtblk_fops = {
.owner = THIS_MODULE,
.getgeo = virtblk_getgeo,
.free_disk = virtblk_free_disk,
.report_zones = virtblk_report_zones,
};
static int index_to_minor(int index)
{
return index << PART_BITS;
}
static int minor_to_index(int minor)
{
return minor >> PART_BITS;
}
static ssize_t serial_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gendisk *disk = dev_to_disk(dev);
int err;
/* sysfs gives us a PAGE_SIZE buffer */
BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
buf[VIRTIO_BLK_ID_BYTES] = '\0';
err = virtblk_get_id(disk, buf);
if (!err)
return strlen(buf);
if (err == -EIO) /* Unsupported? Make it empty. */
return 0;
return err;
}
static DEVICE_ATTR_RO(serial);
/* The queue's logical block size must be set before calling this */
static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize)
{
struct virtio_device *vdev = vblk->vdev;
struct request_queue *q = vblk->disk->queue;
char cap_str_2[10], cap_str_10[10];
unsigned long long nblocks;
u64 capacity;
/* Host must always specify the capacity. */
virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9);
string_get_size(nblocks, queue_logical_block_size(q),
STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
string_get_size(nblocks, queue_logical_block_size(q),
STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
dev_notice(&vdev->dev,
"[%s] %s%llu %d-byte logical blocks (%s/%s)\n",
vblk->disk->disk_name,
resize ? "new size: " : "",
nblocks,
queue_logical_block_size(q),
cap_str_10,
cap_str_2);
set_capacity_and_notify(vblk->disk, capacity);
}
static void virtblk_config_changed_work(struct work_struct *work)
{
struct virtio_blk *vblk =
container_of(work, struct virtio_blk, config_work);
virtblk_update_capacity(vblk, true);
}
static void virtblk_config_changed(struct virtio_device *vdev)
{
struct virtio_blk *vblk = vdev->priv;
queue_work(virtblk_wq, &vblk->config_work);
}
static int init_vq(struct virtio_blk *vblk)
{
int err;
unsigned short i;
vq_callback_t **callbacks;
const char **names;
struct virtqueue **vqs;
unsigned short num_vqs;
unsigned short num_poll_vqs;
struct virtio_device *vdev = vblk->vdev;
struct irq_affinity desc = { 0, };
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
struct virtio_blk_config, num_queues,
&num_vqs);
if (err)
num_vqs = 1;
if (!err && !num_vqs) {
dev_err(&vdev->dev, "MQ advertised but zero queues reported\n");
return -EINVAL;
}
num_vqs = min_t(unsigned int,
min_not_zero(num_request_queues, nr_cpu_ids),
num_vqs);
num_poll_vqs = min_t(unsigned int, poll_queues, num_vqs - 1);
vblk->io_queues[HCTX_TYPE_DEFAULT] = num_vqs - num_poll_vqs;
vblk->io_queues[HCTX_TYPE_READ] = 0;
vblk->io_queues[HCTX_TYPE_POLL] = num_poll_vqs;
dev_info(&vdev->dev, "%d/%d/%d default/read/poll queues\n",
vblk->io_queues[HCTX_TYPE_DEFAULT],
vblk->io_queues[HCTX_TYPE_READ],
vblk->io_queues[HCTX_TYPE_POLL]);